Pork farms are known to produce a large quantity of liquid manure which is difficult to deal with environmentally. In the province of Quebec, Canada, for example, recent legislation was introduced to severely restrain the allowable contaminant concentration limits for water that is unleashed in the environment (via rivers or by watering fields for example). The major concern which led to this is that the contaminants in water, when in sufficiently high concentrations, are known to progressively work their way down into the earth and contaminate the water table. Although a portion of liquid manure from pork can be dealt with by composting, liquid manure typically includes a large percentage of water which must be reduced before the composting operation. Water is typically removed from the liquid manure by filtering and evaporation, but many contaminants form azeotropes with the water and tend to evaporate with it. Therefore, contaminants tend to follow the water vapor and upon condensation, the water still includes concentrations of contaminants which exceed the stricter environmental standards imposed by the government for liberating the water into the environment (into a stream or by irrigating a field for example). Pork producers are thus faced with a considerable challenge in disposing of the liquid manure from their swine.
There is thus a need for an improved process of treating contaminated water.